Windmills (now in the form of wind turbines) have been used for millennia to convert the wind’s kinetic energy into mechanical energy. As early as 200 B.C., mechanical energy was used for specific tasks including grinding grain and pumping water. Nowadays, wind turbines harness kinetic energy from the air and convert it into electricity via a generator.
Much like solar PV installations, you can purchase a domestic wind turbine to supply as much or as little electricity as you want. If you are hoping to limit your dependence on the mains as much as possible, you will need a larger turbine, or multiple smaller turbines. If you are simply looking to produce enough electricity for a light in your garden shed, you can get away with a very small turbine.
Below we look at the different types of wind turbine system you can install in your property.
Battery-less grid tied systems
Battery-less grid tied systems are the simplest, most effective and most environmentally-friendly wind turbine systems. Their role is simple: to produce the most electricity possible to provide electricity for your home and also feed into the grid. Due to the availability of grants such as the feed-in tariffs in the UK, this type of system has grown enormously in popularity in recent years. In these installations, the home owner can effectively sell the surplus energy back to the utility company. There are no batteries in the system, so this removes a lot of the system complication and maintenance. The lack of batteries also makes it cheaper to install.
If your aim is to become completely unreliant on the grid, then you need to ensure the electricity produced by your battery-less grid tied system is in excess of your total electricity usage for the year. However, this system should suit most budgets, because it will reduce reliance on the energy companies, by significantly reducing your bills. If you cannot produce all your electricity, the shortfall is simply made up with electricity from the grid.
There is one major drawback with this setup, and that is that if there is a electrical power cut then you will have no power for your home, because the inverter your energy goes through is connected to mains power, so you may require a generator (powered by diesel or oil) as a back-up policy.
Grid-tied system with battery backup
This is essentially the same as the grid-tied system above, but has a bank of batteries which means that if there is a grid power cut, the inverter can still get the electricity it requires to operate, so the installation will keep providing you with electricity. The constraints of this system are primarily associated with the batteries, which are expensive and require regular maintenance. Finally, add extra inefficiency into the system (ranging from 5 – 40%) and this is added to the constraint side.
This system has no connection at all to the grid, relying instead on batteries to operate if no wind is blowing. However if the capacity of these batteries is too low, then you could be without any power for a prolonged period of time. Having a system off-grid presents an ideal situation as you become completely independent from the grid, and you produce all the electricity you need. However, this type of system tends to be the most expensive and also is maintenance-heavy. If you have a garden shed that needs lighting then this system can work out relatively cheaply, but as soon as you are looking to upscale then it becomes very expensive.
In the next section we look at the components that you need for a successful wind turbine installation.
Wind turbines allow you to produce 100% clean, free electricity.
Wind turbines can be considered a bit of an eyesore and often have to be limited to rural areas.
Entirely dependent on the size of the wind turbine, from £1k – £10k.
Wind turbines on a commercial scale
For wind turbine basics and an explanation on how they work, please visit the Wind Turbines section. The major difference between residential and commercial is the scale. While a wind turbine on your house may produce some or all of your electricity needs, a wind farm (a collection of commercial wind turbines) can provide electricity for many thousands of houses.
While most residential wind turbines tend to be less than 50kW, the largest commercial turbines found on wind farms are now in excess of 6MW. The largest turbine to date, the Enercon E-126 has a hub height of 135m, and a rotor diameter of 126m. It was originally designed to produce 6MW of electricity, but the capacity has been upped to 7.5MW. This one wind turbine can provide enough electricity for approximately 5000 households.
Maximising the power produced by a wind farm
There are numerous features that commercial wind turbines use to maximise the amount of power they produce.
Firstly the pitch of the rotors is automatically altered to catch the most wind. The yaw angle is a misalignment between the direction of the wind and the turbine pointing direction, therefore the turbine is actively controlled by an automated wind vane to minimise this angle – again maximising the power of wind.
Many old style wind turbines rotate at the same speed regardless of the wind strength due to a gearing system within the generator, however new turbines including the E-126 are gearless, with the blades rotating at whatever speed generates the most electricity. Gearless generators are more efficient, as energy is not lost via the gearing system.
The towers tend to be at higher altitudes as at altitude the surface aerodynamic drag is lower, so wind speeds are higher and more constant.
Finally the blades are made from glass-fibre reinforced polyester or wood-epoxy, so they are lighter than old style turbines, and they can therefore accelerate quicker to adapt to wind strength.
What is a wind farm?
Onshore vs. offshore wind power
A wind farm is a collection of commercial size wind turbines located either inland (onshore) or out at sea (offshore). Onshore wind has a much bigger presence in the UK at the moment, just because the technology to support it has been around for much longer than offshore wind. Therefore onshore wind at the moment provides a much higher percentage of the total energy mix than offshore wind in the UK.
In the UK, both onshore and offshore wind farms are subsidised through the Renewables Obligation Certificates (ROCs), with onshore wind farms supported by 1 ROC and offshore wind farms by 2 ROCs. As the UK is a member of the EU, subsidising industry goes against the spirit of the Single Market, however the exceptions exist in the renewable energy generation sectors.
This is because to get to a level playing field for wind power with the current fossil fuel technologies, European governments need to give these renewable industries a helping hand to encourage investment. As has been seen elsewhere in the industry, in the medium term, where investment has been followed by innovation, the price of these technologies has fallen. As a result in the UK, the governments have reduced ROC support gradually as this technology has become more price competitive.
The level of support for offshore wind farms needs to be greater as the technology is more expensive and there is quite a way for it to go before it reaches competitiveness vs. the fossil fuel technologies. Bloomberg New Energy Finance (BNEF), however calculates that the output cost of electricity by onshore wind from 2016, will reach parity with fossil fuels. This is to be driven by further efficiencies and developments in the technology.
Onshore and offshore wind in Europe
In Europe, the largest wind farm currently in production is the £4.5bn Markbygden Wind Farm based in Northern Sweden. This project will be finished by 2020 and will comprise of 1,101 turbines, made up of the E-126 turbines and Enercon E-101 (3MW outage), covering 450km2. The total energy output of the farm will be 12 terawatt hrs/year (TWh), which will be equivalent to the domestic consumption of 2 million houses per year.
As well as building wind farms on land, many offshore projects are being built around the continent. Europe is the leader in offshore wind energy, with the first farm being built in Denmark in 1991. As of 2010 there were 39 offshore wind farms located in waters across Europe. Like in the UK, the opinion is that offshore windfarms are now preferred over onshore windfarms because they are less obtrusive than those built on land, and their noise and size is mitigated by their location away from urban areas.
In addition, water has less surface roughness than land, so the average wind speed is higher out at sea so, thereby increasing the electricity generating capacity of these farms. However, there are environmental impacts to consider for offshore wind turbines – their construction can destroy fishing habitats, and there is a large amount of oil needed to lubricate efficient operation of turbines which has the potential to leak and affect the marine ecosystem.
Wind power development
Wind power is intermittent, only producing electricity when the wind blows and the blades are spinning, so without storage, wind power cannot be aligned to the demand fluctuations very easily. Many larger power stations also lack flexibility in their production of electricity, for example, a nuclear or coal power station produces the same amount of electricity every minute, and this electricity cannot be stored.
Throughout the day there is differing demand for electricity, so during night the demand is lower than at dinner time for example. Therefore, within the electricity mix there needs to be a variety of sources to deal with this fluctuation in demand and one of the most flexible is hydroelectric. This can be turned on and off within seconds to meet any extra demand. Tethering of wind turbines to hydroelectric facilities is currently being investigated; by using the wind power to pump the water back to the top reservoir, the whole system requires no external power support so is completely green and is therefore a very flexible electricity production method.
UK commercial wind power policy
In the UK, there is a largely confusing message projected concerning the future of wind power. While many scientists, investors and environmentalist groups are unequivocal in their support, others have voiced their opposition, particularly on the subject of onshore wind. Although onshore technology is now developed and building windfarms is relatively cheap, environmentalists have objected to more being built as they further blight an already disappearing countryside. Those that support onshore wind have criticised successive governments for reducing, and signalling further reductions in the ROC support.
Offshore wind has been hailed as ‘the future’ for renewable power and a technology where UK engineering can really excel, and export that expertise for the benefit of growing a low carbon economy. Bodies like the Energy Intensive User Group, on the other hand, object to the level ROC support for offshore wind (currently 2 ROCs as mentioned above), and call for a solution that is based on economics and cost – such as increased efficiency measures, increased nuclear and increased onshore wind.
Despite the confusing messages, investment and implementation of onshore and offshore wind continues in the UK and in particular Scotland. For example, in early 2012, SSE, announced that it had surpassed 1GW of energy generation from its onshore wind farms. Further investment is being planned by companies such as Infinergy, Vattenfall and Gamesa in both of these two technology areas. Offshore however is going to require more technological advancement before it sees accelerated growth and energy cost parity with other technologies.
In Europe, the trend has continued to accelerate commercial wind development. There is much ongoing research into wind turbines and the aim is to increase their capacity and output. Denmark is leading the way with ambitious target setting – planning to deliver half of its renewable energy output with wind power. Other big projects include: (1) Norwegian company Sway is currently building a 10MW turbine that is due for completion this year (although it will undergo two years of testing); (2) Plans afoot to build a 15MW turbine off the coast of Spain by 2015, called the Azimut.
Read our thoughts on the future of wind power here.
To maximise the electricity contribution that a wind turbine can provide you with, two interlinked questions need to be considered:
How much electricity you would like to produce?
How much electricity you can produce on your property?
How much electricity do you need your turbine to produce?
You first you need to decide exactly what you are trying to achieve by installing a wind turbine on your property. Are you trying to become completely independent from the grid? Are you simply trying to decrease you electricity bills having received a capital lump sum that you can invest? Do you simply want a wind turbine to power a light in your garden shed? Obviously the larger the turbine, the more electricity it will produce; however larger turbines will be more costly.
By looking at utility bills from previous quarters, you can get a feel for your total electricity usage over a year. You can get more accurate readings if you go around your property and complete an energy assessment of your current load (simply the total energy that each appliance in your house uses over a certain period of time). This involves producing a table with each appliance, its draw in watts (measured using a watt plug in meter – sometimes known as a wattmeter), and the estimated time of use in a 24 hour cycle. With all this information you can complete a much more accurate total yearly assessment of usage of your house (by multiplying usage for a 24 hour cycle by 365 days).
Having a feel for your total energy usage should help you decide what you are trying to achieve with your turbine. There are several wind turbine setups which we have described in more detail below.
How much electricity can your system produce?
It is really important that you have a target electricity figure in your mind that you are aiming to achieve, be it 50% of your total energy requirements, or becoming fully self sufficient. However, this may not be possible if there are constraints on your property, such as lack of space or low average wind speed.
This is the key factor and we usually use average wind speed as the measurement for your particular location. You cannot directly affect the average wind speed at your home; however your choice of site and tower height can have a dramatic impact on the wind resource. The power available for the wind that is blowing is the cube of the wind speed – this is absolutely fundamental, and this can be seen in the simple sums below:
3mph – 3 x 3 x 3 = 27kWh
6mph – 6 x 6 x 6 = 216kWh
12mph – 12 x 12 x 12 = 1,728kWh
This is excellent news, as the further you get away from the surface of the earth and its many obstructions (e.g. houses), the higher the wind speed: therefore the more power in the wind. This means it is important to try and maximise the height of any tower you use, to try to maximise the wind potential of your wind turbine system.
The swept area is the circle that the turbine produces when spinning, so this is the diameter of the blades. The blades are driven by the power in the wind, so the larger your swept area, the more energy you can harness. Again the easiest way to illustrate this is with some more simple sums (apologies for those adverse to maths!), where the area of a circle is half the diameter2 x π. (π = 3.14)
3 foot diameter = 1.5 x 1.5 x 3.14 = 7ft2
6 foot diameter = 3 x 3 x 3.14 = 28ft2
12 foot diameter = 6 x 6 x 3.14 = 113ft2
Taking into account these two factors, you can see the maximum electricity you can produce. Remember that wind speed is free (although towers obviously cost more money the higher they are), while investing in bigger and bigger turbines gets more expensive.
What size turbine should you be looking at?
The size of your wind turbine is therefore determined by the amount of electricity you are looking to produce (but potentially constrained by windspeed and space), and secondly the amount of cash you have available.
Unlike solar photovoltaic cells that can be added to fairly easily as additional funds become available, the turbine blades would need to be replaced, and potentially the generator changed if you want to produce more power in the future. Home scale generators normally are between 8 and 25 feet in diameter (so a swept area of between 50 – 500 feet2). If you have an average wind speed of 10 mph, these could produce between 1,000 and 15,000 kWh. An average house uses approximately 4,800 kWh per year, so a 25 foot diameter turbine is going to produce a serious excess of power to sell back to the grid, or power more than one house.
Final thoughts on wind turbines
Contact your local council to ask about planning permission if you’re considering installing a wind turbine. The majority of local authorities are keen to encourage the installation of renewable energy systems. However it is a good idea to consult your neighbours before investing time and money into the planning phase, to allow them to voice any objections.
Average wind speed
Before you even consider investing in a wind turbine, you need to check your average wind speed. The Carbon Trust have created a tool that allows you to estimate the wind yield at your home location. You are looking for an average wind speed in excess of 5m/s. By providing simple information regarding your location and type of turbine, the tool will give you average wind speed and potential energy output.
In the UK, as a wind turbine owner you can benefit from the Feed-in tariffs. There are different allowances depending on the power output of your equipment. Wind turbines above 5MW are classified as commercial and alternatively benefit from the Renewable Obligation Certificates. The Feed-in tariffs basically provide you with a source of income for every kWh of electricity you produce. This is independent from any excess electricity you sell back to the grid, which you further benefit from in the form of the export tariff. This can really help a wind turbine become an economically viable system to put into your house.
When air hits the wind turbine, the blades spin, converting the wind’s kinetic energy into mechanical energy. This rotary motion then travels down the shaft and drives a generator where the electricity is produced. Typically most wind turbines are mounted in the horizontal plane (like the propeller of a plane), and therefore it is key the blades are facing directly into the wind.
The yaw angle is the difference in angle between the wind direction and the direction in which the rotors are facing. The aim is to minimise the yaw angle as much as possible, so most residential wind turbines tend to have tails which orientate the turbine to best capture the wind. Wind turbines should therefore be able to rotate 3600 on yaw bearings.
There are 2 main styles of urban wind turbines:
Horizontal Axis Wind Turbines (HAWT)
This is a propeller type rotor mounted on the horizontal axis. As mentioned previously, the blades need to be aligned with the wind and this is done by either a simple tail, or an active yaw. These are more efficient at producing electricity than VAWTs however they are impacted more by changes in wind direction.
Vertical Axis Wind Turbines (VAWT)
These are aligned in the vertical axis (like the rotor blades on a helicopter). These are only really deployed within urban areas, where the flow of air is more uneven. Due to their alignment, wind direction has little impact on this type of turbine; however it is apparent that these are less efficient than their HAWT cousins.
In addition to HAWTs and VAWTs there are hybrid turbines that are cylindrical (imagine a gyroscope) – such as the energy ball.
At TheGreenAge, we suggest sticking with the HAWTs as they are the more proven technology, and are offered by more suppliers, so you will be able to get better value for money.
Most turbines tends to have two or three blades, two bladed turbines are cheaper but suffer from blade chatter which puts stress on the system, which can lead to increased maintenance further down the line. If you can afford to get a three bladed turbine, we suggest doing so, as these don’t suffer from this problem at all.
Three types of tower exist: tilt-up, fixed guyed and free standing. The purpose of these towers is to position the turbines in the best possible position to take advantage of the wind.
Tilt-up towers are held in position by four guy ropes one of which can be released, allowing you to lower the tower, so you can work on the turbine.
Fixed guyed towers are similar to tilt-up towers, except they are permanently fixed in place so you need to climb the tower to do any maintenance.
Free standing towers have no guy ropes. As such they require a very solid foundation. Therefore these are certainly the most expensive, but may well be the most aesthetically pleasing.
Most wind turbines produce AC current, so this should be able to be directly fed into your home and the grid, however the voltage and frequency of the power produced is very erratic, so an inverter is used to convert the erratic AC to DC, then back to a smoother AC which can be synchronised with the grid, or for use directly into your home. Battery-based wind turbines normally operate at 12 or 48 Volts, and therefore the inverter must also act to convert this relatively low voltage to high voltage (UK mains is 240 volts). Battery-less systems may produce electricity with a voltage significantly higher (100 volts or more). Therefore in this situation, the inverter needs to be able to handle this higher voltage.
In most wind turbine systems, the electricity does not power any appliances directly. Instead the electricity produced is stored in deep-cycle lead acid batteries which look very similar to the ones found in most cars today (although structurally different). The two most popular types of battery are GEL and Absorbed Glass Mat (AGM), which store the charge very well and do not degrade nearly as fast as the common lead acid (wet cell) battery. Both types of batteries are designed to gradually discharge slowly and recharge 80% of their capacity hundreds of times.
An automotive battery is a shallow-cycle battery, and this is designed to discharge only about 20% of its electricity so is unsuitable for solar photovoltaic cell set-up. The reason is that if any more than 20% is drawn more than a few dozen times, it will get damaged and no longer take charge.
Wind turbine batteries tend to operate at 12v, and can be arranged in banks (multiple batteries), increasing the storage potential of your wind system set up. A bank of batteries organised in a series increases the capacity of your storage but also increases the voltage delivered from your bank; while multiple batteries organised in a parallel circuit increase the capacity, but the voltage stays the same.
Charge controllers are used in wind turbine systems to prevent the batteries from being overcharged. If you decide to implement a grid tie system, a charge controller is not necessary, as any excess electricity that you don’t use at any particular moment is sold directly back to the grid. However, for any battery setup, a charge controller is necessary as it prevents damage to the battery by monitoring the flow of electricity in and out. If your system overcharges the battery it will damage it. The same is also true if you completely discharge all the charge held within the battery.
Most charge controllers associated with wind turbines have dump load capability associated with them. This allows any additional charge to be diverted from the batteries when they are full, potentially to a hot water heating system (so the electricity is not completely wasted). Obviously if you are connected to the grid, this electricity would instead be sold there, providing you with an additional income stream.
Most charge controllers are also equipped with maximum power point (MPPT) charging. The principle of MPPT is to extract the maximum available power from the wind turbine by making them operate at the most efficient voltage (known as the maximum power point voltage). The algorithm included in the MPPT charge controller compares the output from the wind turbine with the battery voltage and then fixes it at the best charging voltage, to get the maximum charge into the battery.
Disconnects are simply switches that allow you to isolate parts of the system so you can troubleshoot or repair faulty parts without the risk of being electrocuted. In addition many wind turbine systems are grounded, so that if there is surge in current anywhere in the system it is safely dissipated rather than damaging the system or more importantly you!
Installing a wind turbine
Are you thinking about installing a wind turbine at home? We have scoured the country for the best tradespeople, so that we can make sure we only recommend those we really trust.
If you would like us to find you a local installer to help install a wind turbine at home, just fill in the form below and we will be in touch shortly!
Whitelee Onshore Wind Farm, Scotland
Whitelee Wind Farm Key Facts
Whitelee Wind Farm is situated on Eaglesham Moor, near Glasgow, Scotland. ScottishPower Renewables first identified the site in 1999, although it took another seven years for work to actually commence on the wind farm, with the first wind turbine erected on 14th November 2007. It is now the largest onshore wind farm in the UK (and in Europe) with 140 turbines producing a combined 322MW of energy, which is enough electricity to power 180,000 homes.
Whitelee Wind Farm Operations
Following the successful rollout of this 1st phase of development, ScottishPower Renewables got planning permission from the Scottish Government to extend the wind farm by building another 75 turbines; which are due to be completed later in 2012. These extra turbines are set to produce an additional 217 MW of electricity taking the total installed capacity to a potential 539 MW; enough to power an estimated 304,000 homes.
The 140 turbines currently in operation are produced by Siemens and have a rotor diameter of 101m, which are designed to spin and therefore create electricity when wind speed is in excess of 4m/s, however maximum electrical output will be when the wind speed is in excess of 13m/s. If the wind goes above 25m/s, the turbines will cease operation for safety reasons.
In April 2012, ScottishPower Renewables decided to seek planning permission for a further small extension of five additional turbines; permission for this is still yet to be decided.
Whitelee Wind Farm Funding
The Whitelee Windfarm is being developed and operated by ScottishPower Renewables (SPR), which is part of Iberdrola Renewables, the largest renewable energy company in the world.
Walney Offshore Wind Farm, England
Where Is The Walney Offshore Wind Farm?
In early 2012, The Walney Offshore Wind Farm was completed approximately 15km off Walney Island, Cumbria in the Irish Sea. The 102 turbines have a total generating capacity of 367.2MW, which should provide 320,000 houses with 100% clean electricity, when transported onshore from these offshore Wind Farms.
Walney Wind Farm Operating Capabilities
The instillation of the Walney Wind Farm was done in two phases. The first phase or Walney 1 was started in Spring 2010 consisting of 51 Siemens 3.6MW turbines, which took a year to install. Phase 2 or Walney 2 also consisted of 51 turbines, but the instillation time was halved; only taking 6 months to complete. Walney 1 & 2 combined area coverage is situated over 73km2
Both Walney 1 and Walney 2 have independent substations located out at sea which increase the voltage of the turbines from 33kV to 132kV so that it can be fed into the grid, via 43km export cables.
The turbines will spin and therefore create electricity when wind speed is in excess of 4m/s, however maximum electrical output will be when the wind speed is in excess of 13m/s. If the wind goes above 25m/s, the turbines will cease operation for safety reasons.
The installation of the wind farm has so far created 60 jobs, helping to boost the local job market and develop the expertise in the engineering sector.
In this weeks blog we are going to look at the advantages of onshore wind turbines. In the UK, wind energy plays a significant role in our energy mix, providing enough electricity to power 4.5m homes in total.
Onshore wind has an installed capacity of 5,619MW, roughly twice that of offshore wind, and produces about 13,000GWh of electricity, enough to power about 3m homes per year.
There has been lots of press attention recently over the role of wind turbines in our energy mix, so we are going to weigh up what we see as the potential advantages and disadvantages of this form of renewable technology.
Advantages of Onshore Wind Turbines
It is a proven Technology
It is already helping provide a significant amount of electricity to the grid. In 2010, onshore electricity provided about 7TWh of electricity to the grid, approximately 25% of the renewable energy in the energy mix in the UK.
It is thought that this might be as high as 30TWh by 2020.
It is comparatively Cheap
Onshore Winds primary advantage is that it is the cheapest renewable energy source currently available to the UK, working out at about 8p / kWh. This puts it slightly more expensive that gas and the other more established fossil fuels which come in about 4-7p / kWh, but is substantially lower than situating the turbines out at sea.
It is quick to install
While a nuclear power station might take in excess of 20 years to construct from the initial planning permission phase, a wind turbine can go up and start providing electricity to the grid in a matter of months.
Limitations of Onshore Wind Turbines
Not 100% Green
So are wind turbines completely green? Well no, despite producing emission free electricity when in operation, they are limited emissions associated with their manufacture and installation.
Some people who live in close proximity of the wind turbines complain of the noise they make when the wind is blowing. The infographic from GE demonstrates how loud wind turbines actually are.
Onshore wind turbines are often criticised for their visual impact, ruining what previously have been areas of natural beauty. They are typically spread out over larger areas than other energy producing installations, and therefore have a larger impact on the local environment.
They don’t produce electricity 24/7
The other major issue with any type of wind turbine is that it produces electricity intermittently. This wouldn’t necessarily be an issue if we could store the electricity produced when demand is very low, but energy storage is currently very inefficient, expensive and unproven.
The Future for Wind Turbines
If the cost of manufacturing wind turbines falls, then very quickly the cost per kWh of electricity produced from wind will reach parity with electricity made from burning fossil fuels.
Potentially, as the wind industry continues to grow, economies of scale can be introduced (ability to make something cheaper, the more you make of it) and the technology will become more efficient (for example, nanotechnology allowing the blades to capture more of the kinetic energy in the wind) so the price to produce the electricity from wind turbines will continue to fall.
There are initiative solutions to make renewables produce power 24/7 currently in development. The Crescent Dunes Solar power plant takes advantage of molten salt technology to keep electricity flowing while the sun doesn’t shine.
In theory, Wind Turbines could be coupled with pumped storage such as the Dinorwig power station in Wales, but even that storage mechanism is limited, and requires a lot more energy to create the electrical potential energy, than can be used for useful work.
Have a look at our energy storage section to see other potential solutions that make make 24/7 production viable.
The last point here, and the one that I think is most important, is that as people begin to grow up with wind turbines around them, they will become the norm and therefore more accepted. Currently many of the people complaining about them have seen these things installed in the last 5 years or so, so knew what the land was like before they were there.
Children growing up now will know no different, the wind turbines will simply be ‘part of the furniture’ and therefore they will recognise them as what they are, simply smaller scale energy power plants.
According to RenewableUK, there are now 370 wind farms in the UK, providing just under 20,000,000,000 KWh of electricity to the grid each year. Based on an average house using 4,500 of electricity per year, 20 billion KWhs is enough to power approximately 4.5 million homes. It is thought that the Government are keen to increase the installed capacity considerably over the next 2 decades, which is exemplified by the fact that in 2012, installed capacity leapt by 30% from 2011 levels.
Wind power cost per MWh
Despite producing 100% renewable, clean energy and currently having a substantial presence in the UK energy mix, wind turbines still seem to get quite a lot of bad press. The onshore wind farms in the UK get a hard time because people feel they ruin the aesthetic beauty of our ‘green and pleasant lands’. Wind turbines in the sea might seem a better idea then, since wind speed is higher and more consistent out at sea, but they get a bad rap because they are considerably more expensive than the land based wind farms. From a price point of view they are actually almost double in cost – electricity from onshore wind turbines costs about £90 / MWh, while electricity from offshore wind turbines costs about £160 / MWh (according to Imperial College London).
A new installation method devised by the clever folks at Universal Foundation may help to dramatically decrease the installation cost of wind farms out at sea.
Current wind power installation methods
There are currently 4 methods of installing wind turbines out at sea, which are described briefly below.
Monopiles – consist of a large steel rod, which is embedded into the sea floor, with a hydraulic hammer, often with the length above and below the seabed, roughly the same, to provide the stability for the wind turbine to sit on top of it. This is much like hammering a pole into the ground with a sledgehammer. The majority of offshore wind turbines are held in place in this manner, and this method of installing the turbines is currently the cheapest and easiest.
Gravity Based Structures – Rather than inserting these structures into the seabed like monopoles, these simply sit on top of it. The GBS are filled with concrete, sand or metal, to anchor them in position.
Space Frame Structures – Like monopiles these are embedded into the ground, but consist of multiple thinner tubes (normally arranged in a tripod layout), providing a much stronger structure. As such the space frame structures work well with wind turbines that sit in deeper waters.
Floating Structures – These are still in the design phase, but do very much what they say on the tin. They float within the water, allowing you to situate them in water of any depth, although the focus of research is trying to make them stable in this deeper water.
New wind power innovation
The new design uses suction bucket technology. It is essentially an upside down steel bucket (with a diameter of 16m), which is inserted into the seabed. A suction pump is then turned on, which sucks the water out of the bucket that causes it to sink easily into the sea floor. Once the bucket is fully inserted into the ground, the pump is turned off, and the bucket is stuck fast into position, allowing the wind turbine to be attached to it above the surface.
So what makes the new wind power design so special?
Well firstly, a lot less iron needs to be used, because a hollow bucket is used instead of a large solid rod (in the case of the monopile). In addition, no expensive, loud hydraulic hammers are needed to drive it in position, the suction bucket should nestle into position very easily (using the suction pump and simple gravity) providing an incredibly stable footing. The suction bucket also can be installed much quicker than existing technologies.
These benefits will all act to drive down the cost of offshore wind turbines to bring them more in line with the onshore turbines. Since an estimated £90bn (according to the Carbon Trust) will be spent on these turbines in the next 20 years, this technology could ensure we get much more turbine for our buck!
The technology is being tested in the North Sea over the next few days, so here’s hoping a simple idea has the potential to revolutionise the offshore wind turbine industry!
Warren Buffett – The Man With A (solar PV) Plan!
January 10, 2013
2013 started pretty well for the renewables industry with news that Warren Buffett is investing a further £1.5bn in what will become the largest solar PV development in the world.
Mr Buffett is widely regarded as the most successful investor of modern times. Although coming from a fairly privileged background, his shrewd investments resulted in him amassing billions of dollars. In 2012 he was voted the fourth richest man in the world with a net worth of around $46.4bn, according to Bloomberg.
Time and time again Mr Buffett has made the right investment decisions, despite an uncertain market, therefore if he feels that now is the time to expand his investment in renewables, one can take it as a very positive sign that they are going to play a major role in the future, not just because the ‘greenies’ are banging the drum, but because they are going to offer excellent returns.
The latest investment sees Mr Buffett’s MidAmerican Energy Holdings investment company striking a deal with SunPower to acquire and build 2 solar PV projects in California. The two projects acquired by Mr Buffet have a combined capacity of 579MW, and will be completed in 2015. In December 2011, his investment company acquired another 550 MW solar PV plant from First Solar. Already MidAmerican Energy Holdings has invested more than $10bn in wind and solar energy, and we hope there is more to come!
According to a report completed by the Federal Energy Regulatory Commission’s Office of Energy Projects, for the first nine months of 2012, 43.8% of the new capacity added in the US was from renewable sources (e.g. wind, solar, biomass, geothermal and water power). Renewables accounted for 13% of total electrical generation during the first six months of 2012 in America.
In the UK, renewables supplied 11.7% of our energy requirement in Q3 2012, but this figure may have been significantly higher if there had been more rainfall during the year (hard to believe, but there were actually hosepipe bans in place in March 2012!). The installed capacity for 2012 was also up 46% on the previous year, due to large wind projects being completed and the conversion of the Tilbury Power Plant to run on biomass.
So despite all the doom and gloom around the economy, it appears investment in renewable energy is looking very healthy!
The US Presidential Candidates and their Green Credentials – A UK Point-of-View
October 16, 2012
Update 8th November 2012: Since this article was written Mr Obama has won a second term as President of the United States. You can see our thoughts on what impact this may have over the next 4 years at the bottom of the post.
The first all-nighter I ever pulled was to watch the 2000 Presidential Election between George W Bush and Al Gore (the latter becoming an outspoken individual on climate change). In the months leading up to the election, I became obsessed: I was following anything that would allow me to have a better understanding of which way the vote would fall. It all culminated on the first Tuesday of November, the box office event itself, the US Presidential Election.
This particular event was particular fascinating to me as it had a very British feel to it, reflecting our love of cricket – it all ended up a score draw after more than 5 days of play!!
Two further presidential elections have since passed, and we are on the eve of the 2012 Presidential election. Since I have been following it, I get the sense that energy security and the environmental agenda are resonating with more and more of the US electorate.
Since the early 2000’s, oil price have gone from an average $20 to over $100 per barrel, which has led to a 3-fold increase in price at the pumps. At the same time, domestic heating bills in the US have gone through the roof (in much the same way as the UK). The need for the USA to have a steady, uninterrupted supply of fuel and for home owners to be able to access this fuel at a reasonable price and use it more efficiently will resonate as being an important issue with potential voters.
The purpose of this blog (from the other side of the pond) is to examine more closely what each presidential candidate is saying about these policies. This blog isn’t a judgement of their past performance, but more a balanced appraisal what they have delivered so far, which should help us try and predict what they might do over the next 4 years should they get elected.
Some political analysts have said that the environment and energy policy is one of the areas that the candidates can clearly be distinguished in terms of their views, while others have also said there’s not a whisker between the two when it comes to these issues.
Let’s first turn to the incumbent candidate the president of the United States – Barack Obama, and examine the positive and regressive steps he has taken on sustainable energy and the environment.
Mr Obama’s view on the Environment & Clean Energy
You don’t have to go back that far to see how Mr Obama feels about the environment – in fact, you only need to look back at what was said about the subject at the recent Democratic Party National Convention. Mr Obama made clear in his speech that he will support investment in renewables (such as wind & solar PV), because he is concerned about the effects on the environment. In addition, he has also championed other solutions like the ‘greening’ of the US motor industry, which has now seen a record number of hybrid and electric models being rolled off the production line and on the US highways.
Mr Obama’s political record
Ever since Mr Obama has held political office in Capitol Hill as a Senator, he has frequently voted fro pro environmental measures. He has consistently supported trying to get the US to rely less on oil imports, whilst at the same time aimed to promote research and use for environmentally energy to balance the US energy supply. For example, in 2005 he backed the then McCain – Lieberman amendment, which would have established an earlier version of a cap-and-trade system. He had also spoken in favour for other carbon emission amendments and policies that supported use of cleaner techniques for industry and road travel.
As President, Mr Obama was widely credited by international press for trying to pass the American Clean Energy and Security Act of 2009 through Congress, which would have effectively have established a limits to the amounts of carbon dioxide emitted in the US. The bill would also have established carbon permits, which companies could have bought and sold to emit carbon. However, although this bill was passed by the House of Representatives and gave Mr Obama plus points for environmental policy credentials, the bill died soon after in the Senate, where it was met by staunch opposition.
He has to be praised for the way he handled the BP oil disaster off the Gulf of Mexico in 2010. While robustly publicly naming and shaming a British organisation was seen as a bit heavy handed in the UK, in hindsight, it was the correct approach and set a firm tone on how oil companies should operate and conduct themselves when it comes to oil drilling and exploration.
One can argue that Mr Obama was staying true to his election pledge of making the US less reliant on oil when earlier this year he signalled his opposition to the extension of the Keystone Pipeline. In the time he has been President, we have seen a record number of renewable energy projects kick off, such as: seeing a fourfold increase in solar PV farms started or being built; nearly doubling of total energy being produced by biomass and wind, an unprecedented amount of federal funds being directed into energy efficiency and carbon emission projects.
However, Mr Obama hasn’t gone far enough
Recent assessment of history through shows that Mr Obama’s administration has shown a much lower appetite to bring in policies and initiatives on the environment. The reason behind it that the economy and safeguarding American jobs has been the most important issue in the US since the economic downturn in 2007/08, and talking about the environment in this situation has been dismissed as being out of step and out of touch with the American voters.
Countering the ‘anti-oil drilling expansion’ points mentioned above, Mr Obama actually just before the Gulf of Mexico oil spill voted in favour of easing offshore drilling. Also, he was a major critic of the Keystone Pipeline, but has recently disappointed environmentalists by seemingly siding with a more measured building programme. In addition, since Mr Obama has been the President, oil output levels in the US have actually increased and have returned to their pre-2003 levels.
These points, looking from the outside, are contradictory to his rather pro environment stance as given prior to getting elected, and his more recent green rhetoric leading up to the 2012 Presidential campaign.
What do we think Mr Obama will do if he was re-elected?
We see more of the same policies on the environment and clean energy from Mr Obama in his second term as President. We don’t believe we will see a cap-and-trade system introduced any time soon in the US, with the recent Democratic convention highlighting that Mr Obama doesn’t necessarily carry the voices of the whole party when it comes to this issue.
A second term will probably lead with more measured initiatives, such as once again focusing of improving vehicle efficiency and ensuring more cars on the road pass that critical 35.5 miles to the gallon range. Under Mr Obama in his second term, we should also see more nuclear power expansion, with the Fukushima disaster not abating the appetite for this power source in the US any time soon.
We don’t see federal spending on subsidies for solar PV, wind and biofuels stopping any time soon, but with pressure to reduce the federal budget from next year, we may see major cuts for these industries, just as we saw here with the feed-in-tariffs in the UK in 2012.
As mentioned, with oil output in the US increasing under Mr Obama, measures to support shale gas fracking will be central to the long term energy solution, but so will energy capture measures, which Mr Obama wants to see implemented on power stations up and down the country to reduce the carbon emissions and increase the state of welfare for local communities.
Let’s turn to the Republican Party challenger – Mitt Romney– and examine the positive and regressive steps he has taken on sustainable energy and the environment.
Mr Romney’s view on the Environment & Clean Energy
The view of the Presidential candidate Mr Romney (since the Presidential candidate selection process started) is to make the US more self sufficient when it comes to energy use and decreasing the barrel of oil imports. While Mr Romney is also for developing clean energy, he is firmly against what he calls ‘crony capitalism’ to enable this – which is federal intervention and using central government tax dollars to subsidise green programmes. While he was in public office as the governor of Massachusetts, he has accepted that there are man-made forces at work which have caused the warming of the planet. But how does his previous political record stack up on these issues and what does the crystal ball say about what type of green policies he would push through if he were elected as President?
Mr Romney’s political record on the environment
When Mr Romney was the Governor of Massachusetts, he pushed through policies that were pro environment and pro conservation. While he was in office he made many statements stating that he believed in climate change and was pro interventionist policies that would encourage renewable energies.
An example of his clean energy agenda, as Governor, he appointed a prominent environmental advisor, Douglas Foy, to oversee some of the programmes that were subsequently introduced. Throughout his time as Governor, his state saw the launch of over 70 initiatives including: trying to tax vehicle emissions, cleaning up factories and using tax and spend policies to promote the growth of clean energy generation. He supported ambitious targets such as aiming to generate 15% of the state’s energy from renewables and cutting 25% of Co2 emissions from state agencies by 2020.
In the 2000’s, Mr Romney had clearly been pro active in trying to be on the side of public health and using the state executive powers to put forward policies that are seemingly now more out of character with his current Presidential campaign. In addition, he also wanted to limit offshore drilling, and was at one stage an advocate of a regional cap-and-trade carbon emission mechanism.
What we think Mr Romney would do if he were elected as President
Time magazine’s recent article described Mr Romney’s attitude to energy policy as “drill baby, drill”, which was an assessment of a 21 page energy white paper he produced for this presidential campaign. The paper leads us to believe that a Romney administration would likely relax oil drilling restrictions, cut regulation and approve the completion of the Keystone pipeline which Mr Obama has opposed.
While Mr Romney is still for the development of energy technology and funding research in this area, he is not about to do so at the expense of fossil fuels. While he wants to have a ‘level playing field’ for energy generation, he contradicts himself, as he doesn’t support removing subsidies for already quite profitable oil companies. Our crystal ball says that Mr Romney is not about the halt drilling and shale gas fracking activities, which have recently led to the US once again being a net oil and gas exporter.
Most international pundits are slightly more pessimistic about the US committing itself to a second, more ambitious round of carbon emission targets under his stewardship. Then again, even Mr Obama’s current administration wasn’t too willing to accept a global way forward at last year’s Durban summit.
Looking at the year so far where we have had heat waves, droughts, wildfires and hurricanes, it’s hard not to think that all these extreme weather events have had nothing to do with climate change. Our assessment is that both candidates see the importance of climate change as an issue, with Mr Obama directly addressing this problem, but with Mr Romney acknowledging it as an issue but prioritising energy security through the expansion of fossil fossils.
Whoever becomes the next President of the United States will have an almighty challenge on their hands. The US economy has never hit the highs it saw in 2007 and to an extent; deficit spending has been a major component in keeping the economy there afloat. So whoever is in the White House will have to make some tough decisions about where federal dollars are spent. It is easy in those situations to slash energy policy development budgets and spend less on environmental conservation, but at what ultimate cost?
The UK model is by no means perfect, and in fact our current government should be doing a lot more, but it has maintained the feed in tariffs and invested a chunk of money towards research into renewables, because over the pond there is more of a consensus that if you invest in green fuels now, it will pay off in the long run with cheaper and more secure energy supply.
Update on Green policies debated at the 2nd Presidential Debate:
At the 2nd Presidential debate in New York on the 16th October, Mr Obama and Mr Romney clashed on energy policy. Mr Obama argued for more green energy solutions such as biofuel, wind power and solar PV as well as extending programmes to encourage energy efficiency in generation and transportation. Mr Romney on the other hand argued for more oil drilling and an expansion in coal production, with a view to make North America energy self sufficient. Mr Obama in our view had slightly more convincing arguments in this debate to answer to some of the current problems in energy security and the challenges on the environment.
Update: 8th November 2012, Mr Obama wins a 2nd Term
Mr Obama having won the election, in his victory speech said that he doesn’t want future generations to be blighted by ‘destructive’ effects of global warming. His call to action on the environment in this speech could be taken as signal that during his 2nd term, there will be renewed focus on giving climate change and renewable energy the appropriate focus they deserve!
At a domestic level to signal a renewed focus on the environment and clean energy, we expect continued support (underpinned by tax breaks) for renewable technologies such as wind and biofuels from the President. In addition, we expect Mr Obama to be less willing to support additional subsidies on fossil fuels and cool the expansion of drilling and fracking activities. However this may be tough given that these industries support quite a number of jobs.
However we appreciate that many bold initiatives such as taxing carbon and even resurrecting the 2009 Cap & Trade bill will be very challenging give a divided Congress. On a high note, we hope the next 4 years means more ‘green’ jobs, more clean energy and smarter ways on how energy is consumed in the US.
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